BEIRUT: Syrian troops and militia backed by Russian warplanes mounted what appeared to be their first major coordinated assault on Syrian insurgents Wednesday and Moscow said its warships fired a barrage of missiles at them from the Caspian Sea, a sign of its new military reach.

The combined operation hit towns close to the main north-south highway that runs through major cities in the mainly government-held west of Syria, said the Syrian Observatory for Human Rights.

Ground attacks by Syrian government forces and their militia allies using heavy surface-to-surface missile bombardments hit at least four insurgent positions and there were heavy clashes, the head of the Observatory, Rami Abdel-Rahman, said.

The Lebanese group Hezbollah took part in the fighting, according to a regional source who is familiar with the military situation in Syria.

Abdel-Rahman said later there was no sign that Syrian troops and their allies had made any tangible advances on the ground. They briefly entered one town, but were forced to retreat, he said, and around 15 of their tanks or armored vehicles had been either destroyed or disabled.

Meanwhile, Russia ended high-level military talks with Israel with a call on other countries, including a suspicious United States and aggrieved Turkey, to coordinate operations in Syria.

The two countries discussed how they could avoid accidentally clashing while operating in Syria.

The talks followed a meeting in Moscow between Israeli Prime Minister Benjamin Netanyahu and Russian President Vladimir Putin during which the two men agreed to set up teams as Russia stepped up military support for Syrian President Bashar Assad.

The areas targeted in Wednesday’s combined assault are held by other rebels, some U.S.-backed, fueling accusations by Russia’s critics that its real aim is to help the government.

Moscow says it shares the West’s aim of preventing the spread of ISIS, and Russian Defense Minister Sergei Shoigu told Putin during a televised meeting that four Russian warships in the Caspian Sea had launched 26 missiles at ISIS in Syria earlier in the day.

The missiles would have passed over Iran and Iraq to reach their targets, covering what Shoigu described as a distance of almost 1,500 km, the latest display of Russian military power at a time when relations with the West are at a post-Cold War low over Ukraine.

The terrain-hugging Kalibr cruise missiles, known by NATO by the codename Sizzler, fly at an altitude of 50 meters and are accurate to within 3 meters, the Russian Defense Ministry said.

The air campaign in Syria has caught Washington and its allies on the back foot and alarmed Syria’s northern neighbor Turkey, which says its air space has been repeatedly violated by Russian jets.

Russia’s most senior diplomat in Israel said that Israel had no reason to fear Russia’s presence or actions in Syria.

Drobinin said Russia was starting similar military talks with Turkey and he hoped these would take place too with other countries, including the U.S.

Syrian state television quoted a military source as saying the missiles fired by Russian ships targeted 11 ISIS positions in Raqqa, Aleppo and Idlib.

The missiles destroyed bomb-making factories, command posts, weapons and ammunition and fuel depots, as well as “terrorist training centers,” the TV said.

Russian airstrikes destroyed the main weapons depots of a U.S.-trained rebel group, the Liwa Suqour al-Jabal, their commander said.

In conversation with Shoigu, Putin said it was too early to talk about the results of Russia’s operations in Syria and ordered his minister to continue cooperation with the U.S., Turkey, Saudi Arabia, Iran and Iraq on the crisis.

U.S. Defense Secretary Ash Carter said the United States would not cooperate militarily with Russia in Syria, although it was willing to hold discussions to secure the safety of its own pilots bombing ISIS targets in Syria.

The Pentagon said U.S.-led coalition aircraft bombing Islamist militants in Syria had been re-routed at least once in the last six days to avoid a close encounter with Russian planes.

The Russian Defense Ministry, meanwhile, said Washington’s refusal to share intelligence with it about the positions of ISIS militants showed the United States was looking for an excuse not to fight terrorism.

“Our partners from other countries who see a real enemy in ISIS which must be destroyed actively help us with data about bases, warehouses, command points and terror training camps,” Maj.-Gen.l Igor Konashenkov, a ministry spokesman, was quoted as saying by the RIA Novosti news agency.

“But those who seem to have a different opinion about this terrorist organization are constantly looking for reasons to refuse us cooperation in the fight against international terrorism,” he said, referring to Washington.

Turkish Prime Minister Ahmet Davutoglu said only two of 57 Russian airstrikes in Syria so far had hit ISIS, while the rest had been against the moderate opposition, the only forces fighting the hard-line insurgents in northwestern Syria.

Russia’s military buildup in Syria included a growing naval presence, long-range rockets and a battalion of troops backed by Moscow’s most modern tanks, the U.S. ambassador to NATO said.

“There is a considerable and growing Russia naval presence in the eastern Mediterranean, more than 10 ships now, which is a bit out of the ordinary,” Douglas Lute told reporters ahead of a meeting of alliance defense ministers in Brussels.

Abdel-Rahman said Russia appeared to have stuck to air support Wednesday. The assault followed a report by Reuters last week that allies of Assad, including Iranians, were preparing to recapture territory lost by the government to rebels in rapid advances this year.

Hezbollah-run Al-Manar television said in a newsflash that “an operation by the Syrian army started in a number of villages and towns in the northern countryside of Hama province.”

A video posted by the media office of an opposition group in Hama province on YouTube purported to show heavy rocket strikes by pro-government forces Wednesday hitting an area in the northern Hama countryside.